Added support for 32bit per pixel subformat, uncompressed, in BMP. Last 8 bit are used as Alpha channel.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@4427 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

CHANGES

@@ -2,6 +2,7 @@ CHANGES IN FLTK 1.1.7
 
 	- Documentation fixes (STR #648, STR #692, STR #730, STR
 	  #744, STR #745)
+	- Added 32bit BMP Image file format support (STR #918)
 	- Value Sliders would not receive focus when clicked on (STR #911)
 	- Added redraw of some widgets to show focus change (STR #910)
 	- Fl::set_font would not clear 'pretty' name (STR #902)

src/Fl_BMP_Image.cxx

@@ -186,6 +186,10 @@ Fl_BMP_Image::Fl_BMP_Image(const char *bmp) // I - File to read
   if (depth == 16)
     use_5_6_5 = (read_dword(fp) == 0xf800);
 
+  // Set byte depth for RGBA images
+  if (depth == 32)
+    bDepth=4;
+
   // Setup image and buffers...
   d(bDepth);
   if (offbits) fseek(fp, offbits, SEEK_SET);
@@ -398,6 +402,15 @@ Fl_BMP_Image::Fl_BMP_Image(const char *bmp) // I - File to read
 	    getc(fp);
 	  }
           break;
+		  
+      case 32 : // 32-bit RGBA
+         for (x = w(); x > 0; x --, ptr += bDepth) {
+            ptr[2] = (uchar)getc(fp);
+            ptr[1] = (uchar)getc(fp);
+            ptr[0] = (uchar)getc(fp);
+            ptr[3] = (uchar)getc(fp);
+          }
+          break;
     }
   }